Yes i can argue on my point but the main point is its not necessary what i think particularly same thing hit your mind. I myself never used any 660cc JDM but i do own a Vitz 2001 from a year.
so let me start, few months back a friend of mine bought an EK Wagon full option which was 2011 model and 2012 import, just used it for 2 weeks max and sold her. Reason behind? He bought it for fuel consumption issues and she gave him 13-15 km/l max but it was not worthy when we talk about summer season in Pakistan. Here the road temperature rises upto 50 degrees or more and the majority of the citizens use their car as a family car so normally a car loaded with 4-5 persons with AC on and the engine is 660cc so it feels like driving a Honda CD70 on tripling, not to mention engine wont last long. Secondly, road trips are part of life weather its for fun or for business and we need more space for luggage even for a comfortable drive which these 660cc lacks a big time. Parts are even expensive plus all of them already comes massively meter tempered and not to mention ugly shapes and body material equal to tin cans :-#
On the other hand lets talk about Vitz - 1000cc motor and even way better than our local 1000cc Cultus or Coure. Fuel efficient i.e 12-15 km/l depending upon driver's driving style. Parts are easily available and i am sure not more expensive than the new 660cc JDM (i am referring to the old shape Vitz). Massive space for luggage and for a comfortable drive, we can say its a Corolla without trunk. There is absolutely no major price difference between a new 660cc JDM and a 2001-04 Vitz, infact you may find a Vitz even cheaper. What else you want? If you want more fuel efficient vehicle go buy a Prius but please dont ever compare a 660cc and a Vitz.
660cc comparison comes when someone plans to buy a Mehran!